Android虚拟导航键的显示隐藏实例

package test.lb.com.myapplication;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity implements View.OnClickListener{
 boolean isnight = false;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  Button nightbutton = (Button) findViewById(R.id.nightbutton);
  Button hidebutton = (Button) findViewById(R.id.hidenav);
  Button fullbutton = (Button) findViewById(R.id.full);
  Button fullOnly= (Button) findViewById(R.id.fullonly);
  nightbutton.setOnClickListener(this);
  hidebutton.setOnClickListener(this);
  fullbutton.setOnClickListener(this);
  fullonly.setOnClickListener(this);
 }
 @Override
 public void onClick(View v) {
  switch (v.getId()){
   case R.id.nightbutton:
    if (isnight){
     v.setSystemUiVisibility(View.SYSTEM_UI_FLAG_VISIBLE);
    }else{
     //夜间模式，系统控件颜色会变暗
     v.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
    }
    isnight = !isnight;
    break;
   case R.id.hidenav:
    //隐藏虚拟按键，点击又会重新出现
    v.setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
    break;
   case R.id.full:
    //在隐藏显示系统控件的过程中不会来移动我们的控件
    v.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE|
      //隐藏系统状态栏，如果设置了Window.FEATURE_ACTION_BAR_OVERLY同时隐藏Actionbar
      View.SYSTEM_UI_FLAG_FULLSCREEN|
      //这个会隐藏屏幕上的所有系统控件
      View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
    break;
   case R.id.fullonly:
    v.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN);
  }
 }
}